A goal from Martyn Woolford killed off Derby after they twice dragged themselves level against Scunthorpe.The winger scampered clear of the Rams' rearguard and fired home to put his side ahead for a third time after Gary Hooper's two first-half goals.
Hooper's close-range finish opened the scoring before Paul Green burst onto Stephen Pearson's pass to equalise.
Paul Hayes played in Hooper to put the Iron in back front, but a foul on Green saw Kris Commons slot home the penalty.
After an uneventful opening spell, the game burst into life as Stephen Bywater spilled Woolford's shot and Hooper pounced to prod home from inside the six-yard box.
Derby responded inside three minutes with Green's measured right-footed finish past a sprawling Murphy.
Hayes and Hooper's partnership up front caused the Derby backline plenty of problems and both strikers wasted chances before combining to put their side ahead.
But the visitors were handed a way back into the game as Murphy tripped the onrushing Green and Commons kept his cool from the spot.
The Scotland forward almost put Nigel Clough's side ahead soon after but his shot was cleared by a covering defender as it crept towards an empty net.
However, Woolford had the final say in a see-saw match as he raced clear down the right and found the net.
Scunthorpe manager Ian Adkins: "Hayes and Hooper were a massive threat all the way through - the team compliments them.
"It's not long before the transfer deadline so it will be interesting.
"You look at Hayes and Hooper and there is bound to be people banging on the door after that performance."
Derby manager Nigel Clough:
"We've come back from 1-0 down and 2-1 down and we should be protecting the point that we've got.
"We have experienced players trying to win instead of ensuring we don't lose.
"The fact we're scoring goals is always a good sign, but the problem we've got is that it shouldn't be at the expense of conceding at the other end."